The reduction in price target by RBC Capital, a reputable financial institution, could lead to a negative short-term sentiment among investors, potentially causing a decrease in Gran Tierra Energy's stock price. The maintenance of a 'Sector Perform' rating indicates that the analyst sees the company as adequately valued at its current price, but the lowered price target suggests a recalibration of expectations, possibly due to underlying challenges or market conditions affecting the company's future performance.